Data storage cartridge having a reduced thickness segment

ABSTRACT

A data storage cartridge is described. The cartridge may include a housing having a top, a bottom, a front side, a back side, a first lateral side, and a second lateral side, said housing having a first media access aperture on the top of the housing; and a data storage medium contained within the housing, the data storage medium including a disk with a top and a bottom; wherein the front side of the housing contains a first segment of reduced thickness adjacent to the first media access aperture.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.60/491,875, filed Jul. 31, 2003, the disclosure of which is incorporatedherein in its entirety as if fully set forth below.

BACKGROUND OF THE INVENTION

Data storage cartridges have been used to house removable data storagemedia. FIGS. 1A-1B show one type of data storage cartridge 100comprising a housing 102 containing a magneto-optical (MO) disk medium104. The configuration and design of this MO cartridge 100 conforms tostandards set by the ECMA Technical Committee TC31, which provides auniform standard that can be followed by MO cartridge and MO drivemanufacturers. This standard was published by ECMA as “StandardECMA-322, Data Interchange on 130 mm Magneto-Optical DiskCartridges—Capacity: 9,1 Gbytes per Cartridge” (June 2001), which isincorporated by reference herein in its entirety as if fully set forthbelow.

The housing 102 serves as a protective enclosure for the disk medium 104and includes access windows 106 covered by a sliding shutter 108. Adetent 110 is provided in the shutter 108 to enable a loading mechanismin a data drive to engage and slide the shutter 108. When the MOcartridge 100 is inserted into an MO drive in the loading direction L, ashutter opening mechanism in the MO drive engages the detent 110 to openthe shutter 108 and uncover the windows 106, thereby exposing a portionof the MO disk 104. The MO disk 104 may consist of two sides assembledtogether with their recording layers on the inside. Data can be writtenonto both sides of the disk 104 as marks in the form of magnetic domainsin the recording layer and can be erased from the disk 104 with afocused optical beam, using a thermo-magnetic effect. The data can beread with a focused optical beam, using the magneto-optical effect.

Another type of data storage system is known as holographic storage,described in detail in U.S. Pat. No. 5,719,691, entitled, “PhaseCorrelation Multiplex Holography,” to Curtis et al., issued Feb. 17,1998, and U.S. Pat. No. 6,191,875, entitled, “Process for HolographyUsing Reference Beam Having Correlated Phase Content,” to Curtis et al.,issued Feb. 20, 2001, incorporated by reference herein in theirentireties. Holographic data storage systems store information or databased on the concept of a signal beam interfering with a reference beamat a holographic storage medium. The interference of the signal beam andthe reference beam creates a holographic representation, i.e., ahologram, of data elements as a pattern of varying refractive indexand/or absorption imprinted in a volume of a storage or recording mediumsuch as a photopolymer or photorefractive crystal.

In holographic data storage (HDS), light from a coherent laser source issplit into two beams, signal (data-carrying) and reference beams.Digital data to be stored are “encoded” onto the signal beam via aspatial light modulator (SLM). The data are arranged into data pages orlarge arrays, and these data pages are translated into pixels of thespatial light modulator that either block or transmit light. The lightof the signal beam traverses through the modulator and is thereforeencoded with the “checkerboard” pattern of the data page. This encodedbeam then interferes with the reference beam through the volume of aphotosensitive recording medium, storing the digital data pages. Theinterference pattern induces modulations in the refractive index of therecording material yielding diffractive volume gratings. The referencebeam is used during readout to diffract off of the recorded gratings,reconstructing the stored array of bits. The reconstructed array isprojected onto a pixelated detector, such as a CMOS photo-detector arrayor the like. The detector reads the data in parallel, and the data canthen be decoded into the original encoded data.

It may be desirable that the holographic data storage medium be providedin disk form and housed in a cartridge housing similar to the housings102 for MO cartridges 100. This enables HDS manufacturers to utilizeexisting MO cartridge designs and handling mechanisms for easyconversion to HDS applications. However, the HDS medium functionsdifferently from the MO storage medium, and therefore has differenthandling considerations. In particular, the HDS medium is sensitive tolight and can be damaged if exposed to the read/write mechanism of an MOdrive, or even ambient light. If an HDS medium is provided in acartridge similar to the cartridge design of another media type, itwould be desirable to implement protection mechanisms to prevent orinhibit attempts to load and read data from the HDS media using anothertype of non-HDS media drive. In addition, the data transfer mechanismused with certain storage media types, such as, for example, HDS media,may be structurally different from the data transfer mechanisms of othermedia types and may therefore have different design considerations.

Accordingly, there is a need for an improved design for a removable datastorage cartridge housing a data storage medium.

BRIEF SUMMARY OF THE INVENTION

In accordance with embodiments of the present invention, a data storagecartridge is provided. The cartridge comprises: a housing having a top,a bottom, a front side, a back side, a first lateral side, and a secondlateral side, said housing having a first media access aperture on thetop of the housing; and a data storage medium contained within thehousing, the data storage medium comprising a disk with a top and abottom; wherein the front side of the housing contains a first segmentof reduced thickness adjacent to the first media access aperture.

In accordance with other embodiments of the present invention, a datastorage cartridge is provided. The cartridge comprises: a housingcomprising a top shell and a bottom shell, said housing having a housingthickness; and a data storage medium contained within the housingbetween the top shell and the bottom shell; wherein said housing has anaccess side comprising a region of reduced thickness less than thehousing thickness.

In accordance with other embodiments of the present invention, a datastorage cartridge is provided. The cartridge comprises: a housingcomprising a top side, a bottom side, and an access side, the top sideof the housing defining a top plane; and a data storage medium containedwithin the housing; wherein said housing includes an unobstructed accesspath to the data storage medium from the access side said unobstructedaccess path passing through the top plane.

In accordance with other embodiments of the present invention, a datadrive assembly is provided. The assembly comprises: a data drive,comprising a carriage assembly and a data transfer mechanism. Thecarriage assembly is configured to receive a data storage cartridgecomprising: a housing defining a top plane, a bottom plane, a mediaaccess aperture, and a front side containing a segment of reducedthickness; and a data storage medium contained in the housing; whereinthe data drive is configured to receive the data storage cartridge suchthat as the data storage cartridge is loaded into the data drive, aportion of the data transfer mechanism passes adjacent the segment ofreduced thickness and is received in the media access aperture such thatthe portion penetrates the top plane of the housing.

In accordance with other embodiments of the present invention, a datadrive assembly is provided. The assembly comprises: a data drivecomprising a data transfer mechanism, said data transfer mechanismhaving a first component and a second component separated by a firstdistance; wherein the data drive is configured to receive a data storagecartridge between the first component and the second component, whereina maximum thickness of the data storage cartridge is greater than thefirst distance.

In accordance with other embodiments of the present invention, a methodof operating a data drive assembly is provided. The method comprises:receiving a data storage cartridge in a data drive, the data storagecartridge comprising: a housing defining a top plane, a bottom plane, amedia access aperture, and a front side containing a segment of reducedthickness; and passing a first portion of a data transfer mechanism ofthe data drive adjacent the segment of reduced thickness of the datastorage cartridge such that the first portion penetrates the top planeof the housing as the data storage cartridge travels to a fully loadedposition in the data drive.

Other features and aspects of the invention will become apparent fromthe following detailed description, taken in conjunction with theaccompanying drawings which illustrate, by way of example, the featuresin accordance with embodiments of the invention. The summary is notintended to limit the scope of the invention, which is defined solely bythe claims attached hereto.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1B show top and bottom perspective views of a prior art datastorage cartridge.

FIGS. 2A-2B show top perspective views of a data storage cartridge, inaccordance with embodiments of the present invention.

FIGS. 3A-3B show bottom perspective views of a data storage cartridge,in accordance with embodiments of the present invention.

FIGS. 4A-4C show top, side, and bottom views of a top shell of acartridge housing, in accordance with embodiments of the presentinvention.

FIGS. 5A-5C show top, side, and bottom views of a bottom shell of acartridge housing, in accordance with embodiments of the presentinvention.

FIGS. 6A-6B show a shutter lock assembly in a locked position, inaccordance with embodiments of the present invention.

FIGS. 7A-7B show a shutter lock assembly in an unlocked position, inaccordance with embodiments of the present invention.

FIGS. 8A-8B are perspective views of a shutter cam and lock assembly, inaccordance with embodiments of the present invention.

FIGS. 9A-9B are top views of a bottom shell with a lock assembly in thelocked position, in accordance with embodiments of the presentinvention.

FIGS. 10A-10B are top views of a bottom shell with a lock assembly inthe unlocked position, in accordance with embodiments of the presentinvention.

FIG. 11 is an exploded top perspective view of a cartridge, inaccordance with embodiments of the present invention.

FIG. 12 is an exploded bottom perspective view of a cartridge, inaccordance with embodiments of the present invention.

FIG. 13 is a rear perspective view of a data drive assembly with a datastorage cartridge partially inserted therein, in accordance withembodiments of the present invention.

FIG. 14 is a rear perspective view of a data drive assembly with a datastorage cartridge fully inserted therein and with an open shutter, inaccordance with embodiments of the present invention.

FIG. 15 is a perspective view of an access side of a cartridge, inaccordance with embodiments of the present invention.

FIGS. 16A-16B are perspective views of a data drive assembly and datatransfer assembly, in accordance with embodiments of the presentinvention.

FIG. 17A is a top view of a data drive assembly and data transferassembly, in accordance with embodiments of the present invention.

FIG. 17B is a cross-sectional view of the data drive assembly and datatransfer assembly in FIG. 17A.

FIGS. 18A-18B are simplified cross-sectional views of cartridges havingregions of reduced thickness, in accordance with embodiments of thepresent invention.

FIGS. 19A-19C are top, front, and cross-sectional views of a cartridgein accordance with embodiments of the present invention.

In the following description, reference is made to the accompanyingdrawings which form a part thereof, and which illustrate severalembodiments of the present invention. It is understood that otherembodiments may be utilized and structural and operational changes maybe made without departing from the scope of the present invention. Theuse of the same reference symbols in different drawings indicatessimilar or identical items.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 2A-2B are perspective views of a top side of a data storagecartridge 200, in accordance with embodiments of the present invention.The cartridge 200 is also described in “DATA STORAGE CARTRIDGE,” byGregory P. Hertrich, Ser. No. 60/491,875, filed Jul. 31, 2003, and“CARTRIDGE SHUTTER MECHANISM,” by Gregory P. Hertrich, Ser. No.60/492,093, also filed on Jul. 31, 2003, the disclosures of which areincorporated herein in their entirety as if fully set forth below. Thecartridge 200 may comprise a cartridge housing 202 having a data storagemedium 210 provided therein. The housing 202 is formed by a top shell204 and a bottom shell 205. The top and bottom shells 204-205 includemedia access apertures 206 and 207 (shown in FIGS. 3A-3B), which exposea portion of the storage medium 210 contained therein. The top andbottom shells 204-205 may be formed of, for example, injection moldedplastic. Other polymer-based materials or non-polymer-based materialsmay be used to form the shells 204-205. The storage medium 210 may bedisk-shaped, having a top surface, a bottom surface, and a thickness,with a hub 212 provided at the center of the medium 210.

The cartridge 200 may further comprise a slidable shutter 220 having afirst aperture cover portion 222 on the top side of the cartridge 200for covering the top media access aperture 206 and a second aperturecover portion 223 on the bottom side of the cartridge 200 for coveringthe bottom media access aperture 207. FIG. 2A shows the top of thecartridge 200 with the shutter 220 in the closed position, and FIG. 2Bshows the top of the cartridge 200 with the shutter 220 in the openposition. The shutter 220 may further comprise a shutter detent/slot224, which can be used to unlock and open the shutter 220, as will bedescribed in greater detail below. In the illustrated embodiment, thefirst aperture cover portion 222 and the second aperture cover portion223 are formed from a single piece of U-shaped material, such as plasticor sheet metal. In other embodiments, the cover portions 222-223 may beformed of separate components.

The cartridge housing 202 may also include various features that can beused to assist in the handling and storage of the cartridge 200 duringuse. A gripper slot 232 may be provided along each side of the cartridge200 towards the back end of the cartridge 200. The gripper slots 232 maybe used to enable a robotic gripper mechanism to easily grasp thecartridge 200, such as during the loading and unloading of the cartridge200 from a data drive, or when retrieving the cartridge 200 from astorage bay in a cartridge library. Alignment holes 234 may be providedto enable a data drive or other mechanism to precisely locate a knowndatum on the cartridge 200 or to facilitate the identification of thetype of cartridge. An insertion slot 236 may also be provided on eachside of the cartridge 200 towards the front end of the cartridge 200. Adetent 238 may be provided inside the insertion slot 236. The insertionslot 236 and the detent 238 may be used to guide, position, and retainthe cartridge 200 within a data drive during read/write operations tothe data storage medium 210 or may be used by the library cartridgehandling mechanisms.

FIGS. 3A-3B show perspective views of the bottom side of the cartridge200 with the shutter 220 in the closed position and in the openposition, respectively. In these figures, it can be seen that the bottomshell 205 includes a bottom aperture 207 similar to the top aperture 206and alignment holes 235 similar to alignment holes 234. In otherembodiments, a media access aperture may be provided on only one side ofthe cartridge.

FIG. 4A shows the outer side of the top shell 204, with the variousshutter components removed. FIG. 4B is a side view of the top shell 204,and FIG. 4C shows the interior side of the top shell 204. The interiorside of the shell 204 is the side that is adjacent the data storagemedium 210 when the cartridge 200 is assembled. The interior sideincludes a circular region 240 for receiving the disk-shaped storagemedium 210 and four screw mounts 242 for receiving screws used to couplethe top shell 204 with the bottom shell 205. An upper guide slot 246 isprovided for receiving a lip of the shutter 220, which is retained inthe guide slot 246 by guide slot cover 248 (shown in FIGS. 2A-2B).

The top shell 204 also includes an front region 250 that extends beyondthe edge of the storage medium 210 closest to the side of the cartridge200. An upper guide rail 244 is provided along the front region 250 forguiding the shutter assembly and for providing additional stiffness tothe housing structure. An upper optics opening 252 is also provided on aportion of the front region 250 to provide clearance for a read/writeassembly to be mated with the cartridge 200, as will be described ingreater detail below. A portion 254 having a reduced thickness remainsbetween the optics opening 252 and the top media access aperture 206.

FIG. 5A shows the outer side of the bottom shell 205, with the variousshutter components removed. FIG. 5B is a side view of the bottom shell205, and FIG. 5C shows the interior side of the bottom shell 205. Theinterior side of the bottom shell 205 includes a circular region 260that matches circular region 240 on the top shell 204. A shutter camopening 262 and a lower optics opening 264 are provided in the frontregion 250 of the bottom shell 205. A portion 266 having a reducedthickness remains between the lower optics opening 264 and the bottommedia access aperture 207. Screw holes 268 are provided which align withscrew mounts 242 on the top shell 204. The front region 250 of thebottom shell 205 also includes a lower guide rail 270 and a lock latch280. A lower guide slot 272 is provided for receiving a lip of theshutter 220, which is retained in the guide slot 272 by guide slot cover274 (shown in FIGS. 3A-3B).

In accordance with aspects of the present invention, a lock assembly 300(shown, e.g., in FIGS. 8A-8B, 9A-9B, and 10A-10B) may be used to preventaccidental opening of the shutter 220. This may be particularlyadvantageous in applications where the storage medium 210 is sensitiveto light. In such situations, it may be desirable to provide a lock sothat the shutter 220 will not be inadvertently opened during handling orin the event that the cartridge 200 is loaded into the wrong type ofdata drive.

FIG. 6A shows the front side of the cartridge 200, and FIG. 6B is amagnified view of the shutter slot 224, showing a lock actuator 304protruding from a lock actuator opening 302 in the locked position. Withthe lock actuator 304 in the locked position, the shutter 220 cannot beopened. FIGS. 7A-7B show the lock actuator 304 recessed into the lockactuator opening 302, which corresponds to the unlocked position. Whenthe lock actuator 304 is in the unlocked position, the shutter 220 isfree to be opened. Although the precise arrangement of the lock actuator304 and the shutter 220 may vary, in the illustrated embodiment, thelock actuator 304 protrudes from the opening 302 by approximately 0.8 mmwhen in the locked position and is recessed by approximately 1.0 mm whenin the unlocked position. Accordingly, the shutter opener 430 displacesthe lock actuator 304 by approximately 1.8 mm before the shutter 220 canbe opened.

FIG. 8A is an exploded rear view of a shutter cam 330 including the lockassembly 300, in accordance with embodiments of the present invention.FIG. 8B is a front perspective view of the assembled shutter cam 330,shutter return spring 332, and lock assembly 300. The lock assembly 300comprises the lock actuator 304, a locking arm 306, and an actuatorreturn spring 308. The locking arm 306 comprises a first finger 310 anda second finger 312, and is configured to rotate about a pivot hole 318.The second finger 312 includes an aperture 314 that receives a pin 316on the lock actuator 304. The lock actuator 304 is configured to slideback and forth between a first end and a second end of an actuator slot320.

FIGS. 9A-9B are top views of the bottom shell 205 with the lock assembly300 in the locked position. As can be seen in the enlarged view in FIG.9B, when the lock assembly 300 is in the locked position, the lockactuator 304 is biased by the actuator return spring 308 so that it isdisposed on the first end of the actuator slot 320 and protrudesslightly from the lock actuator opening 302. With the lock actuator 304in this position, the locking arm 306 is rotated about pivot hole 318such that the first finger 310 engages the lock latch 280 on the bottomshell 205. This prevents the shutter cam 330 from sliding, therebylocking the shutter 220 closed.

FIGS. 10A-10B are top views of the bottom shell 205 with the lockassembly 300 in the unlocked position. As can be seen in the enlargedview in FIG. 10B, the lock actuator 304 has been urged to the second endof the actuator slot 320 such that the lock actuator 304 is recessedinto the lock actuator opening 302. The pin 316 on the lock actuator 304draws the second finger 312 of the locking arm 306 along with the lockactuator 304, causing the locking arm 306 to rotate. This rotationreleases the first finger 310 from the lock latch 280, thereby freeingthe shutter cam 330 to slide and open shutter 220.

FIG. 11 is an exploded top perspective view and FIG. 12 is an explodedbottom perspective view of the cartridge 200. The shutter cam 330together and the lock assembly 300 are retained between the top andbottom shells 204, 205. The shutter cam 330 is guided by lower guiderail 270 and upper guide rail 244. The lower guide rail 270 and upperguide rail 244 also provide additional structural support for the frontregion 250. Because the bottom shell 205 has the shutter cam opening262, the shutter cam 330 is permitted to slide back and forth within theshutter cam opening 262. The shutter cam 330 is coupled to the coverportions 222, 223 of the shutter 220 such that as the shutter cam 330slides across the shutter cam opening 262, the shutter 220 is moved intothe open position, thereby exposing the storage medium 210.

The cartridge 200 described above may be used in conjunction with a datadrive configured to unlock and open the shutter 220 during the loadingprocess. FIG. 13 is a perspective view of a data storage cartridge 200partially inserted into a data drive assembly 400, in accordance withembodiments of the present invention. The data drive assembly 400 maycomprise the loading mechanism for a data drive, which could beprovided, for example, as part of a data storage library system. Anexemplary data drive assembly 400 is described in the U.S. patentapplication entitled, “DATA STORAGE CARTRIDGE LOADING SYSTEM,” byGregory P. Hertrich, Ser. No. 10/632,659, filed Jul. 31, 2003. Thedescription of the system and its operation in the above-citedapplication is incorporated by reference herein in its entirety as iffully set forth below. Other data drive designs may be used in otherembodiments.

In the illustrated embodiment, a cartridge carrier 404 is configured toreceive the data storage cartridge 200 when in an unload position, asshown in FIG. 13. A carrier loading assembly 410 drives the carrier 404to move from the unload position to a load position such that the hub212 provided in the data storage cartridge 200 is mated with a spindleprovided on a sled 406. The cartridge carrier 404 may further include ashutter opener 430 having a lock release. The lock release comprises aboss 434 having a lock release portion 436 and a shutter opening portion438. The shutter opener 430 is configured to rotate about a rotation pinand is guided in its rotation by guide pin 440, received in guide slot442.

A data transfer mechanism may be mounted onto the drive base for readingdata from and/or writing data to the storage medium 210 contained withinthe data storage cartridge 200. As used herein, the term “data transfermechanism” is defined as a mechanism which can either: (1) read datafrom a data storage medium; (2) write data to a data storage medium; or(3) read data from and write data to a data storage medium. Variousmethods can be used for storing and reading the data, including, e.g.,optical, magneto-optical, magnetic, and electronic. In some embodiments,a holographic read/write assembly may be used as the data transfermechanism.

In the illustrated data drive assembly 400, the loading of the cartridge200 into the carrier 404 is performed manually by the user or by amechanical robotic insertion device, without assistance from the datadrive assembly 400. The boss 434 on the shutter opener 430 may be usedto both unlock the shutter 220 and to slide the shutter 220 to the side,thereby exposing the storage medium 210. The shutter return spring 332(shown, for example, in FIGS. 8A-8B) provides a bias to retain theshutter 220 in the closed position. As shown in FIG. 13, when thecartridge 200 is inserted into the carrier 404 a first distance in thex-direction, the boss 1434 enters the shutter slot 224 in the shuttercam 330. As described above, the shutter lock assembly 300 prevents theshutter 220 from opening unless the lock actuator 304 is depressed.

As the cartridge 200 is inserted deeper into the carrier 404 in thex-direction, the top portion (i.e., the lock release portion 436) of theboss 434, which has a larger diameter than the bottom portion (i.e., theshutter opening portion 438), applies a pressure onto the lock actuator304. As the cartridge 200 continues moving deeper into the carrier 404,the shutter slot 224 applies a force in the x-direction onto the boss434, causing the boss 434 to travel with the cartridge 200 in thex-direction. Because the shutter opener 430 is rotatably mounted to thecarrier 404, the rotational path of travel of the boss 434 causes theboss 434 to simultaneously travel in the negative y-direction (asindicated by the axes illustrated in FIG. 13) as it is pushed in thex-direction by the cartridge 200. This movement enables the boss 434 totravel together with the cartridge 200 in the x-direction, whileapplying a force against the shutter slot 224 in the negativey-direction.

Because the lock release portion 436 and the shutter opening portion 438are differently sized, they contact the shutter cam 330 at differentpoints. In the illustrated embodiment, the lock release portion 436 hasa radius that is 1.0 mm larger than the radius of the shutter openingportion 438. Thus, the upper portion (i.e., the lock release portion436) of the boss 434 causes the lock actuator 304 to be depressed intothe cartridge 200, thereby unlocking the shutter lock assembly 300, asdescribed above. After the shutter lock is released, the lower, smallerdiameter portion of the boss 434 (i.e., the shutter opening portion 438)contacts the edge of the shutter slot 224 and pushes the shutter 220 inthe negative y-direction, thereby opening the shutter 220. In otherembodiments, the upper portion of the boss 434 serves to both unlock thelock actuator 304 and slide the shutter 220 open. The lower portion ofthe boss 434 need not contact the shutter slot 224.

When the cartridge 200 has been fully inserted into the carrier 404, theboss 434 will have drawn the shutter 220 into the fully open position,as shown in FIG. 14. Here, it can be seen that when the shutter 220 isfully open, the top media access aperture 206 in the cartridge housing202 is exposed. Similarly, the bottom media access aperture 207 is alsoexposed. A portion of the top and bottom surfaces of the storage medium210 are exposed by the media apertures 206, 207. As the hub 212 at thecenter of the storage medium 210 is rotated by the drive spindle,successive portions of the storage medium 210 are exposed by the mediaapertures 206, 207. This enables the data transfer mechanism to accessthe complete surface of the storage medium 210.

The unloading of the cartridge 200 is performed in a similar fashion. Asthe cartridge 200 is withdrawn from the carrier 404, two springs may beused to assist in returning the shutter 220 to the closed position.First, the shutter return spring 332 applies a force onto the shuttercam 330, drawing the shutter 220 closed. In addition, a shutter openerspring (not shown) applies a force onto the shutter opener 430, drawingthe shutter opener 430 back to the unload position, as shown in FIG. 13.During withdrawal of the cartridge 200, the boss 434 travels with thecartridge 200 in the negative x-direction. Due to the boss's circularpath, the boss 434 also moves in the positive y-direction, therebyallowing the shutter 220 to close. Towards the end of the path of boss434, as the lock release portion 436 disengages from the lock actuator304, the compressed actuator return spring 308 returns the lock actuator304 to the locked position, thereby locking the shutter 220 until thenext load.

Data storage cartridges in accordance with embodiments of the presentinvention may achieve numerous advantages over conventional cartridgedesigns. For example, the cartridge 200 may have exterior dimensionssimilar or identical to the dimensions of a standard, conventionalmagneto-optical disk cartridge, yet be used with a holographic storagemedium. Adherence to a conventional form factor for the cartridgehousing facilitates the adoption of existing components and handlingassemblies currently used for magneto-optical storage with holographicstorage applications. However, as mentioned above, if a holographicstorage cartridge is loaded into an MO drive, the read/write mechanismof the MO drive could severely damage the holographic media and/or thedata stored thereon. Similarly, if an MO cartridge were loaded into theholographic storage drive, the MO storage medium and/or the MO cartridgehousing could be damaged by the holographic data transfer assembly.

By locating the shutter slot 224 in a different location than the detent110 according to the MO standard, the accidental misleading of one typeof cartridge into the wrong type of data drive may be avoided. Theshutter opening mechanisms of each type of drive would not be configuredto engage the shutter in the expected location of the shutterslot/detent. In addition, the use of a shutter lock can provide furtherprotection against the shutter opening mechanism of a different drivetype accidentally opening the locked shutter.

The positioning of the above-described lock actuator 304 within theshutter slot 224 and the direction of applied force necessary to releasethe lock may further inhibit inadvertent opening of the shutter 220. Inaddition, this design can enable the cartridge to be used with a single,simple shutter opening mechanism to both unlock and translate theshutter 220. The accidental unlocking and opening of the shutter 220 canfurther be inhibited in embodiments that require that the lock actuator304 be depressed sufficiently far that the surface of the lock actuator304 is recessed within the lock actuator opening 302.

In accordance with aspects of the present invention, a data storagecartridge 200 is provided having a housing with one or more regions ofreduced thickness. This may be desirable when the cartridge 200 isutilized with a data drive having a data transfer assembly withcomponents that would be obstructed if the walls of the housing were ofuniform thickness.

FIG. 15 is a perspective view of the cartridge 200, having a top side501, a bottom side (not shown in FIG. 15), a front side 500, a back side503, and two lateral sides 502 a-502 b. The top side 501 defines a topplane of the cartridge 200 and the bottom side defines a bottom plane ofthe cartridge 200. In FIG. 15, the front side 500 is also the accessside of the cartridge 200. The access side is the side of the cartridge200 from which the data transfer assembly approaches when the datatransfer assembly is mated with the storage medium 210 in the cartridge200. In the embodiment shown, the access side is also the side thatincludes the front region 250, defined as the region between the frontside 500 of the cartridge 200 and the edge of the storage medium 210closest to the front side 500.

FIGS. 16A-16B are perspective views of the cartridge 200 loaded into thedata drive assembly 400. In FIG. 16A, the cartridge 200 is approachingthe data transfer assembly 600 and in FIG. 16B, the data transferassembly 600 is mated with the cartridge 200 and is in position to readand write data to and from the data storage medium 210. In theillustrated embodiment, the cartridge 200 is a holographic data storagecartridge and the data transfer assembly 600 is a holographic read/writeassembly. In other embodiments, different data storage technologies canbe used. In addition, the data transfer assembly 600 may enable readingof data only or may enable the reading and writing of data.

FIG. 17A is a top view of the data drive assembly 400 and FIG. 17B is across-sectional view taken along the line A-A in FIG. 17A. FIG. 17Bshows some of the components of the holographic data transfer assembly600, in accordance with embodiments of the present invention. Thesecomponents include an encoder 602 for producing encoded signal beams, adetector 606 for detecting the interference pattern from the storagemedium 210, and a reference beam generator 604 for producing a referencebeam.

As can be seen in FIG. 17A, the encoder 602, the detector 606, and thereference beam generator 604 are positioned relatively close to eachother. In particular, the distance, d₁, between the encoder 602 and thedetector 606 may be smaller than the maximum thickness, t_(M), of thecartridge 200 (as shown in FIG. 15). Therefore, as the data transferassembly 600 is brought towards the access side of the cartridge 200 toposition the storage medium 210 between the encoder 602 and the detector606, the cartridge housing 202 may obstruct these components and preventthe cartridge 200 from entering the data transfer assembly 600. Toprevent such an obstruction, the housing 202 may include one or moreportions of reduced thickness on the access side of the catridge 200 toprovide clearance for the data transfer assembly components.

FIGS. 18A-18B are simplified cross-sectional views of the cartridge 200and a cartridge 200′. In FIG. 18A, there are two regions 610, 612 ofreduced thickness in the front region 250. The maximum thickness, t_(M),of the cartridge 200 is defined as the distance between the planeforming the top of the cartridge 200 and the plane forming the bottom ofthe cartridge 200. The thickness of the first region 610 is t₁, and thethickness of the second region is t₂, wherein t₁ and t₂ are both lessthan t_(M). With this arrangement, the minimum clearance between thedata transfer components is t_(M), which is the distance between the twosurfaces forming the regions 610, 612.

In FIG. 18B, the sum of the thicknesses, t₁+t₂′, is equal to the maximumthickness, t_(M). Therefore, the minimum clearance between the datatransfer components is t_(c)=0. In other words, the minimum necessaryclearance for the data transfer assembly 600 is determined by thethickness of the storage medium 210, not the cartridge housing 202.

FIGS. 19A-19C are top, front, and cross-sectional views of an embodimentof the invention. FIG. 19C is a partial cross-sectional view taken alongline C-C in FIG. 19A, with dimensions in millimeters provided in a 4:1scale. In this embodiment, the regions of reduced thickness 254 and 266are offset to accommodate the offset components of the data transferassembly 600, as shown in FIG. 17B. In other embodiments, the componentsof the data transfer assembly 600 may be aligned in the z-direction, sothat the regions of reduced thickness 254 and 266 may be aligned aswell.

In accordance with other aspects of the present invention, theabove-described shutter 220 and shutter cam 330 arrangement may enablethe shutter 220 and shutter cam 330 to be completely clear of the accessregion (AR), as shown in FIGS. 2B and 15. The access region is the widthof the aperture 206 along the front region 250 of the cartridge 200. Thepositioning of the shutter 220 and shutter cam 330 to the side of theaccess region enables a data transfer assembly to access the datastorage medium 210 without being blocked by the shutter 220 and shuttercam 330. In contrast, in the cartridge 100 shown in FIG. 1B, it can beseen that the cartridge opening detent 110 is positioned within theaccess region. Such an arrangement would decrease the width of theregion which may be provided with a reduced thickness, as describedabove.

Embodiments of the present invention having regions of reduced thicknessdescribed above may provide a data storage cartridge that can be used inconjunction with a data transfer assembly having a small amount ofclearance between components, while also providing a structurally soundhousing that prevents the data storage medium 210 from being exposed toambient light or other contaminants during handling. In someembodiments, the region(s) of reduced thickness may have no thicknesswhatsoever. In other words, the cartridge housing 202 may not extendcompletely across the access region. However, it may be desirable tomaintain some portion of housing across the entire front region of thecartridge to improve rigidity and strength of the cartridge.

Data drive systems incorporating the above-described data drive assemblymay achieve numerous advantages over existing systems. For example, theregions of reduced thickness may provide an unobstructed path parallelto the major surface of the cartridge 200 (i.e., the top side 501) thatextends below the plane defined by the top side 501 of the cartridge. Inother words, the cartridge 200 provides a region having a reducedthickness that extends from the access side of the cartridge 200 to thestorage media 210.

The foregoing description of the preferred embodiments of the inventionhas been presented for the purposes of illustration and description. Itis not intended to be exhaustive or to limit the invention to theprecise form disclosed. Many modifications and variations are possiblein light of the above teaching. For example, although the embodimentsdescribed above refer to holographic storage systems, in otherembodiments the data storage cartridge may use a different data storagemethod, such as, for example, optical storage, magneto-optical storage,magnetic storage, or electronic storage. In the above-describedembodiments, the data storage medium comprises a rotatable disk. Inother embodiments, the data storage medium may take other forms. Forexample, the medium may have different shapes or be immobilized withinthe cartridge. In addition, the configurations of the various data drivecomponents described and illustrated herein may vary in otherembodiments. For example, the arrangement of the encoder 602, thereference beam generator 604, and the detector 606 may vary. In someembodiments, the data transfer assembly 600 may be provided on only asingle side of the cartridge 200.

It is intended that the scope of the invention be limited not by thisdetailed description, but rather by the claims appended hereto. Theabove specification, examples, and data provide a complete descriptionof the manufacture and use of the composition of the invention. Sincemany embodiments of the invention can be made without departing from thespirit and scope of the invention, the invention resides in the claimshereinafter appended.

1. A data storage cartridge comprising: a housing having a top, abottom, a front side, a back side, a first lateral side, and a secondlateral side, said housing having a first media access aperture on thetop of the housing; and a data storage medium contained within thehousing, the data storage medium comprising a disk with a top and abottom; wherein the front side of the housing contains a first segmentof reduced thickness less than a thickness of the front side of thehousing, and wherein the first segment of reduced thickness is adjacentto the first media access aperture and has a length along the front sideof the housing, perpendicular to the thickness of the front side of thehousing, which is less than or equal to a width of the first mediaaccess aperture parallel to the front side of the housing; a secondmedia access aperture provided on the bottom of the housing; wherein thefront side of the housing contains a second segment of reduced thicknessless than a thickness of the front side of the housing, the secondsegment adjacent the second media access aperture and offset laterallyfrom the first segment.
 2. The data storage cartridge of claim 1,wherein: the first segment of reduced thickness defines an openingextending from a plane defined by the top of the housing to a planedefined by the top of the data storage medium.
 3. The data storagecartridge of claim 1, wherein: said housing further comprises a shutterassembly movable from a closed position to an open position such thatthe shutter assembly blocks at least part of the first segment ofreduced thickness when in the closed position and exposes at least partof the first segment of reduced thickness when in the open position. 4.The data storage cartridge of claim 1, wherein: the data storage mediumcomprises a holographic storage medium.
 5. The data storage cartridge ofclaim 1, wherein the top of the housing defines a top plane; and whereinsaid housing includes an unobstructed access path to the data storagemedium from the front side, said unobstructed access path passingthrough the top plane.
 6. The data storage cartridge of claim 5,wherein: said housing further comprises a shutter assembly movable froma closed position to an open position such that the shutter assemblyblocks the access path when in the closed position and exposes theaccess path when in the open position.
 7. The data storage cartridge ofclaim 5, wherein: said data storage medium comprises a holographic datastorage medium.
 8. The data storage cartridge of claim 5, wherein thefront side comprises a reduced thickness region defining a portion ofthe unobstructed access path to the data storage medium from the frontside.
 9. The data storage cartridge of claim 5, wherein a length of theunobstructed access path from the front side is less than or equal to awidth of a media access aperture formed in the top side of the housing.